The basic theories of operation and construction of tuning fork gyroscopes are now fairly well known. Such gyroscopes include a substrate, silicon proof masses with comb electrodes, position sensitive pick-offs, sense electrodes, and inner and outer drives with comb electrodes. The proof masses are suspended above the substrate by a support flexure which permits movement of the proof masses relative to the sense electrode, the drive electrodes and the substrate.
The substrate, which is commonly constructed from glass, has a high electrical resistivity which is partially responsible for voltage transients which can adversely effect gyroscope performance. For example, coupling between comb electrodes is sensitive to such voltage transients. Additionally, the transients impart pick-off sensitivity and undesirable vertical (Z-axis) forces normal to the proof masses. This vertical force and pickoff sensitivity can (a) degrade tuning fork gyroscope performance and (b) prevent the tuning fork gyroscope motor self-oscillator loop from starting.